JP4274264B2 - Module manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a module used for a module or the like to which a shield cover such as a VCO or a high-frequency module is attached.

  Hereinafter, a conventional method for manufacturing a module will be described with reference to the drawings. FIG. 10 is a flowchart of a conventional module manufacturing method. In FIG. 10, reference numeral 1 denotes a sheet substrate in which a plurality of printed circuit boards are connected, and a soldering land is provided at a location where an electronic component (not shown) is soldered.

  Reference numeral 2 denotes a printing process for printing cream solder on the sheet substrate 1, and the cream solder is printed using a screen. Here, the portion where the cover is soldered is a non-printing portion where the cream solder is not printed. In the electronic component mounting step 3, an electronic component (not shown) is mounted on the sheet substrate 1 on which the cream solder is printed.

  Reference numeral 4 denotes a reflow process in which cream solder is melted after the electronic component mounting process and the electronic component is soldered to the sheet substrate 1.

  Reference numeral 5 denotes a cream solder transfer step provided after the reflow step, and the solder paste is applied onto the sheet substrate 1 using a transfer plate having a hole at a position facing the land of the sheet substrate to which the cover is soldered. Is a step of transferring

  Here, the transfer process 5 will be described with reference to the drawings. FIG. 11 is a sectional view of the transfer means in the transfer step 5. In this cream solder transfer process 5, the cream solder 13 is embedded in the hole 12 of the transfer plate 11 having a thickness of about 1 mm, and the push pin 14 that can be inserted into the hole 12 is moved downward (in the direction of arrow A in FIG. 11). The cream solder 13 embedded in the holes 12 is extruded onto the printed circuit board 22 to transfer the cream solder 13 onto the printed circuit board 22. At this time, the cream solder 13 a is pressed onto the printed circuit board 22 by the push pins 14 in order to transfer the cream solder 13 onto the printed circuit board 22 reliably.

  Then, a cover is mounted on the cream solder transferred in the cream solder transfer step by the cover mounting step 6 and heated by the melting step 7 to melt the transferred cream solder and solder the cover to the sheet substrate.

  And the sheet | seat board | substrate 1 with which the cover was soldered is divided | segmented by the division | segmentation process 8, and a module is completed by test | inspecting an electrical property by the test | inspection process 9. FIG. Thereafter, packaging such as taping was performed in the packaging step 10.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2001-313224 A

  However, in such a conventional module manufacturing method, since the transfer plate 11 is thick and the amount of cream solder 13a transferred to the connecting portion increases, the cream when the pressing pin 14 is pressed or the cover is attached is used. Due to the pressing of the solder, the cream solder 13a overflows from the connection portion, and there is a problem that a short circuit occurs with an electronic component or the like inside the cover.

  SUMMARY OF THE INVENTION The present invention solves this problem, and an object of the present invention is to provide a module manufacturing method capable of preventing a short circuit between a connection part and an electronic component due to solder in the connection part.

In order to achieve this object, in the module manufacturing method of the present invention , a connection portion is provided so as to surround a circuit formed of electronic components, and the cover and the cover are provided inside the side surface portion of the cover. The chipped portions for preventing the connection are formed at substantially equal intervals, cream solder is printed on the soldered portion of the electronic component provided on one surface of the printed circuit board and the connection portion, and then the one surface And then soldering the electronic component to the printed circuit board, and then applying a flux to the place where the connecting portion and the bent portion are connected. , the cover and the connecting portion and the bending portion is attached at a position opposite, so then melting the solder of the connecting portion again, formed in the connecting portion during mounting of said cover Is substantially uniformly to shall the height of the solder.

  Thereby, since it has the application | coating process which apply | coats a flux to a connection part, a connection part and a cover can be connected with the solder supplied by the printing process, and the connection part and electronic component by the solder of a connection part and Can be prevented.

As described above, according to the present invention, a printed circuit board, an electronic component mounted on one surface of the printed circuit board, a metal cover provided so as to cover the upper side of the electronic component, and a side surface of the cover part tip bent portion provided with, together with the location corresponding to the bent portion, the printed one Oite on the surface the electronic component connection portion which is provided to surround the circuit constituted by the substrate If, a the printed circuit board other ground formed on the surface electrode together with the connecting portion is connected, it said bending portion and said connecting portion is a module that is connected soldered, the printed circuit board Print cream solder on the soldered part of the electronic component provided on one surface and the connection part, and then attach the electronic component to the one surface, and then melt the cream solder Was soldered the electronic components to the printed circuit board, together with the connecting portion and the bending portion is applying flux to the locations are connected by then, the cover and the connecting portion and the bending portion facing mounted in position, in the manufacturing method subsequent to the connection part module Ru was remelted solder, to the inner side surface portions of the cover in the connecting portion, substantially like the missing portion to block the connection between the cover The solder is formed at intervals, and the height of the solder formed on the connecting portion when the cover is attached is made substantially uniform .

Thereby, since it has the application | coating process which apply | coats a flux to a connection part, a connection part and a cover can be connected with the solder supplied by the printing process. Accordingly, it is possible to realize a module manufacturing method capable of preventing a short circuit between the connection part and the electronic component due to the solder of the connection part. Since the bent portion provided on the entire circumference of the cover 4 is soldered and joined to the connecting portion, a module manufacturing method capable of obtaining a module with good shielding properties can be realized. Moreover, since the front-end | tip part of a cover side surface is bend | folded, the area facing a connection part can be enlarged. Therefore, the cover can be securely soldered at the connecting portion. In addition, since the missing portions are provided at equal intervals, the solder height in the connection portion can be made substantially uniform in the reflow process, the accuracy of the cover mounting position can be improved, and the bent portion of the cover can be spaced from Can be soldered without any problems. Furthermore, since the missing portion is formed inside the side surface portion of the cover, a solder fillet can be reliably formed inside the cover, and the reliability of the soldered portion is enhanced with respect to a thermal shock cycle or the like.

(Embodiment 1)
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 2 is a cross-sectional view of the voltage controlled oscillator according to the first embodiment. In FIG. 2, reference numeral 21 denotes a voltage controlled oscillator (hereinafter referred to as a VCO, used here as an example of a module), which is used for a mobile phone or the like and oscillates a high frequency signal of 1.8 GHz. is there. Since the module 21 is mounted on a mobile phone, its size is as small as 11 mm in length, 12 mm in width, and 1.9 mm in height.

  Next, 22 is a printed circuit board of the VCO 21 and uses a 4-layer board having a thickness of 0.6 mm. Reference numeral 23 denotes a land provided on the one surface 22 a side of the printed circuit board 22, and an electronic component 24 is connected to the land 23 by cream solder 25. Reference numeral 26 denotes a cover connection land (used as an example of a connection portion) provided on one surface 22 a of the printed circuit board 22, and is provided so as to surround a circuit constituting the VCO 21. The cream solders 61a and 61b in the first embodiment are made of tin / silver-based lead-free solder.

  Reference numeral 27 denotes a metal cover, which is formed by drawing in the first embodiment. In this way, since the cover 27 by drawing is used for the VCO, there is no gap due to processing and the shielding property is good. Therefore, a VCO with small oscillation signal leakage can be realized.

  A bent portion 28 is provided at the tip of the side surface portion 27 a of the cover 27, and the bent portion 28 and the land 26 are positioned to face each other. And these bending part 28 and the land 26 are connected by the cream solder 25a. Since the bent portion 28 is formed on the entire periphery of the side surface 27a of the cover 27, the bent portion 28 is connected to the land 26 on the entire periphery of the cover 27, so that the shield can be surely shielded.

  Reference numeral 29 denotes an electrode formed on the other surface 22b of the printed circuit board 22, which is connected to a mother board on which the VCO 21 is mounted.

  In the present embodiment, the electrode 29 is a 1.6 mm square land.

  Next, FIG. 3 is an enlarged view of the ground electrode in the first embodiment. In FIG. 3, conductor non-forming portions 31 are formed at four corners around the ground electrode 29 a, and a connection portion 32 with a ground width of 0.8 mm is formed between the non-forming portions. A 1.75 mm square solder resist film non-forming portion 33 is provided. This makes it difficult for heat to diffuse when the non-forming part 31 solders the VCO to the mother board, so that the solder is easily melted. The ground electrode 29a and the land 26 are electrically connected to each other so that the cover 27 can securely shield them.

  Next, FIG. 4 shows a top view of the printed circuit board in the first embodiment. 4, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is simplified. In FIG. 4, reference numeral 41 denotes a land 26 missing portion, which is provided at approximately equal intervals of about 1.8 mm. In the first embodiment, the missing portion 41 is obtained by forming a solder resist film with a width of 0.3 mm at a predetermined position of the land 26. The missing portion is formed of a solder resist, but this may be formed by missing the copper foil of the land 26 or by providing a through hole.

  Next, a module manufacturing method according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart of the first embodiment, and FIG. 5 is a top view of a printed circuit board in a state where electronic components are mounted on cream solder in the component mounting process. 6 to 9 are sectional views of the cream solder in each process. 1 to 9, the same components as those in FIGS. 2, 3, and 10 are denoted by the same reference numerals, and the description thereof is simplified.

  52 is a screen printing process in which cream solders 61a and 61b (shown in FIG. 5) are printed on a sheet substrate 51 in which 49 print substrates 22 are connected. In this printing step 52, cream solder is printed using a metal screen of about 100 microns. In order to reduce the size of the VCO 21, the interval 62 between the electronic components 24 is set to about 0.15 mm. Further, the cream solder 61 is provided with a non-application portion 63 of about 0.5 mm to 1.0 mm.

  Next, in the electronic component mounting step 3, the electronic component 24 is mounted on the sheet substrate 51 screen-printed in the printing step 52, and in the reflow step 4, the cream solders 61a and 61b are melted. Attach to 22.

  6 is a transverse sectional view of the land 26 in a state where the reflow process 4 is completed, and FIG. 7 is a longitudinal sectional view thereof. 6 and 7, the same components as those in FIGS. 2 to 5 are denoted by the same reference numerals, and the description thereof is simplified. In FIGS. 6 and 7, reference numeral 71 denotes a solder resist film. A part of the solder resist film extends to the land 26 so that the missing portion 41 is formed.

  When the reflow process 4 is completed, the cream solder 61a is once melted and spreads over the land 26 except for the missing portion 41. At this time, the cream solder 61a tends to concentrate near the corners of the land 26 due to the surface tension thereof. Therefore, in the first embodiment, by providing the missing portion 41 in the land 26, concentration due to melting of the cream solder 61a can be prevented, and the height 72 of the entire land after the reflow process 4 can be made substantially equal. Accordingly, the cover 27 can be mounted with high accuracy, and a short circuit with the circuit of the VCO 21 is less likely to occur, so that the VCO can be reduced in size.

  53 is a laser trimming step provided after the reflow step 4, and is a step of trimming the pattern inductance (not shown) of the circuit of the VCO 21 by laser processing to adjust the oscillation frequency to a predetermined frequency.

  54 is a cleaning process for removing fine solder balls by reflow soldering, flux residue, copper foil scraps by laser trimming, and the like after the laser trimming process 53. By removing solder balls, flux residues, trimming debris, and the like by this cleaning step 54, frequency drift due to short circuit between circuits, humidity, and the like can be reduced.

  Next, reference numeral 55 denotes a flux application process, which is a process of applying flux to the bent portion 28 of the cover 27. In this flux application step 55, a squeegee is scraped in the flux pan to form a flux film of about 0.5 mm on the pan. Then, the flux is attached to the bent portion 28 by immersing the bent portion 28 in the flux film.

  Then, the cover 27 to which the flux is applied in the flux application process 55 is attached on the printed circuit board 22 by the cover attachment process 56. At this time, the land 26 and the bent portion 28 are mounted at positions facing each other. That is, in the present embodiment, the flux is supplied to the connection portion between the cover 27 and the land 26 by applying the flux to the cover 27 side.

  Here, FIG. 8 is a cross-sectional view of the main part when the cover is mounted in the first embodiment as viewed from above. In FIG. 8, the cover 41 is mounted at a position where the tip 41 a of the missing portion 41 fits in the inner surface 27 b (FIG. 8) of the cover 27. This prevents the cream solder 61a between the missing portions 41 from spreading and soldering. Therefore, the cover 27 and the land 26 can be securely connected by soldering.

  Reference numeral 57 denotes a remelting step, which is a step of remelting the once-cured cream solder 61a. However, since the flux is applied to the cover 27 at this time, the cream solder 61a is easily remelted. Since the cream solder 61a in the first embodiment is a lead-free solder having a melting point of 217 ° C. to 219 ° C., the remelting temperature in the remelting process is 245 ° C. ± 5 ° C. Further, since the flux is applied to the cover 27 side, the flux can be applied only to the cream solder 61a. Therefore, it is difficult for the printed circuit board cleaned in the cleaning step 54 to be contaminated by the flux.

  FIGS. 9A and 9B are main part cross-sectional views of the VCO in the first embodiment viewed from the side after completion of remelting. FIG. 9B shows a cross section of the missing portion 41. First, as shown in FIG. 9A, between the missing portions 41, the cream solder is also provided between the land 26 and the inner surface 27 b of the cover 27 in addition to the portion where the bent portion 28 and the land 26 face each other. The fillet 61 by 61a is formed. Thereby, the cover 27 and the land 26 are securely soldered.

  On the other hand, the missing portion 41 is soldered at a portion where the bent portion 28 and the land 26 face each other. That is, since the adjacent lands 26 are divided by the missing portion 41, the cream solder 61 a does not flow to the adjacent lands 26. Therefore, the cover 27 and the land 26 can be soldered with certainty.

  With the configuration described above, the cover 27 is soldered using the cream solder 61a printed in the printing step 52, so that it is difficult for the solder 61a of the land 26 to cause a short circuit between the electronic components 24.

  The flux is applied to the bent portion 28 of the cover 27, whereby the cream solder 61a can be remelted and the cover 27 and the land 26 can be soldered.

  Further, since the cover 27 has the bent portion 28, the area facing the land 26 can be increased. Therefore, the cover 27 can be securely soldered.

  Furthermore, by providing the missing portion 41, the height 72 of the cream solder 61a can be made substantially uniform when the cover 27 is attached, and a fillet can be reliably formed between the missing portions. Can be securely soldered between.

  The method for manufacturing a module according to the present invention has an effect that it is possible to prevent a short circuit between the connection part and the electronic component due to the solder of the connection part. It is useful to use it.

The flowchart of the manufacturing method of the module in Embodiment 1 of this invention Same as above, sectional view Same part detail drawing Same top view of printed circuit board Same as above, the top view of the printed circuit board after mounting components Same as above, enlarged sectional view Same as above, enlarged sectional view The main part enlarged sectional view seen from the top (A) Same sectional view, (b) Same sectional view of missing part Manufacturing flowchart for conventional modules Cross section of transfer means in transfer process

Explanation of symbols

3 Mounting process 4 Reflow process 21 VCO
22 Printed circuit board 24 Electronic component 26 Land 27 Cover 28 Bending part 29a Ground electrode 52 Printing process 55 Flux application process 56 Cover mounting process

Claims (4)

A printed circuit board, an electronic component mounted on one surface of the printed circuit board, a metal cover provided so as to cover the upper side of the electronic component, and a bent portion provided at the tip of the side surface of the cover , together provided at a position corresponding to the bent portion, and a connection part provided so as to surround the circuit composed of Oite the electronic component on one surface of the printed circuit board, with the connection portion is connected wherein a printed circuit board the other ground formed on a surface electrode of said bending portion and said connecting portion is a module that is connected soldered electronic components provided on one surface of the printed circuit board The solder paste is printed on the soldered portion and the connection portion, and then the electronic component is mounted on the one surface, and then the cream solder is melted to attach the electronic component to the pre-process. Soldered to preparative substrate, and followed by the connecting portion and the bending portion is applying flux to the locations connected by mounting the cover at a position where said connecting portion and the bending portion is opposed, thereafter in the method for manufacturing a module Ru is melted again solder of the connecting portions, the inner side surface portions of the cover in the connecting portion, forming a cutout portion for preventing the connection between the cover substantially regular intervals, said cover A method for manufacturing a module in which the height of the solder formed on the connecting portion when mounting is substantially uniform . The module manufacturing method according to claim 1, wherein the cover is formed by drawing. The module manufacturing method according to claim 1, wherein a conductor non-formation portion is formed at four corners of the ground electrode . The method of manufacturing a module according to claim 1, wherein the flux is applied to the connection portion between the connection portion and the end portion, the flux is applied to the end portion, and then the cover to which the flux is applied is attached to the printed board. .

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